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select.h
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1/*
2 * Copyright (C) 2019 Freie Universität Berlin
3 *
4 * This file is subject to the terms and conditions of the GNU Lesser
5 * General Public License v2.1. See the file LICENSE in the top level
6 * directory for more details.
7 */
8
29#ifndef SYS_SELECT_H
30#define SYS_SELECT_H
31
32#ifdef CPU_NATIVE
33/* On native, system headers may depend on system's <sys/select.h>. Hence,
34 * include the real sys/select.h here. */
35__extension__
36#include_next <sys/select.h>
37#endif
38
39#include <string.h>
40/* prevent cyclic dependency with newlib/picolibc's `sys/types.h` */
41#if (defined(MODULE_NEWLIB) || defined(MODULE_PICOLIBC)) && !defined(CPU_ESP8266)
42#include <sys/_timeval.h>
43#else
44#include <sys/time.h>
45#endif
46
47#include "bitfield.h"
48
49#ifdef __cplusplus
50extern "C" {
51#endif
52
56#define POSIX_SELECT_THREAD_FLAG (1U << 3)
57
58#ifndef CPU_NATIVE
59
71#ifndef CONFIG_POSIX_FD_SET_SIZE
72#define CONFIG_POSIX_FD_SET_SIZE (16)
73#endif
76/* ESP's newlib has this already defined in `sys/types.h` */
77#if !defined(CPU_ESP8266)
83#define FD_SETSIZE (CONFIG_POSIX_FD_SET_SIZE)
84
88typedef struct {
91} fd_set;
92
99static inline void FD_CLR(int fd, fd_set *fdsetp)
100{
101 bf_unset(fdsetp->fds, fd);
102}
103
113static inline int FD_ISSET(int fd, fd_set *fdsetp)
114{
115 return (int)bf_isset(fdsetp->fds, fd);
116}
117
125static inline void FD_SET(int fd, fd_set *fdsetp)
126{
127 bf_set(fdsetp->fds, fd);
128}
129
135static inline void FD_ZERO(fd_set *fdsetp)
136{
137 memset(fdsetp->fds, 0, sizeof(fdsetp->fds));
138}
139#endif /* !defined(CPU_ESP32) && !defined(CPU_ESP8266) */
140
173int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds,
174 struct timeval *timeout);
175
176#endif /* CPU_NATIVE */
177
178#ifdef __cplusplus
179}
180#endif
181
182#endif /* SYS_SELECT_H */
bitfields operations on bitfields of arbitrary length
static void bf_set(uint8_t field[], size_t idx)
Set the bit to 1.
Definition bitfield.h:56
static void bf_unset(uint8_t field[], size_t idx)
Clear the bit.
Definition bitfield.h:80
static bool bf_isset(const uint8_t field[], size_t idx)
Check if the bet is set.
Definition bitfield.h:128
static int FD_ISSET(int fd, fd_set *fdsetp)
Checks if a file descriptor is a member of an fd_set
Definition select.h:113
static void FD_SET(int fd, fd_set *fdsetp)
Adds a file descriptor from an fd_set if it is not already a member.
Definition select.h:125
static void FD_ZERO(fd_set *fdsetp)
Initializes the descriptor set as an empty set.
Definition select.h:135
int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout)
Examines the given file descriptor sets if they are ready for their respective operation.
#define FD_SETSIZE
Maximum number of file descriptors in an fd_set structure.
Definition select.h:83
static void FD_CLR(int fd, fd_set *fdsetp)
Removes a file descriptor from an fd_set if it is a member.
Definition select.h:99
The fd_set structure.
Definition select.h:88
BITFIELD(fds, FD_SETSIZE)
Bit-field to represent the set of file descriptors.
Definition of struct timeval for the atmega.
Definition time.h:23